Centrifugal pump system



March 19, 1963 Y b. JQKUNZ 3,081,981

CENTRIEUGAL PUMP SYSTEM Filed Feb. 17, 1959 2 Sheets-Sheet 1 CHARLES J KUNZ INVENTOR BY fM Ji 0% A TTORIVEYS March 19, 1963 c. J. KUNZ 3,

CENTRIFUGAL PUMP SYSTEM Filed Feb. 1'7, 1959 2 Sheets-Sheet 2 CHARLES J. KU/VZ INVENTOR.

BY XwZ M ATTORNEYS United Statesv Patent 3,081,981 CENTRIFUGAL PUMP SYSTEM Charles J. Kunz, Rochester, N.Y., assignor to Eastman Kodak Company, Rochester, N.Y., a corporation of New Jersey Filed Feb. 17, 1959, Ser. No. 793,756

7 Claims. (Cl. 259-96) ing to prevent air from leaking into the system and to eliminate the need for a shaft packing gland are well known in the art. A pump of this type is described in US. Patent No. 1,295,621, W. A. Simond. The primary disadvantages of pumps and pumping systems of this type are that they are of relatively complicated construction, thereby increasing the criticality of the manufacturing tolerances involved, increasing the cost of manufacture, and providing a pump system that'is diflicult to assemble and disassemble without necessitating the aid of special equipment. Applicantis improved pump. system is believed to obviate these disadvantages of prior known pump systems.

Therefore, one of the primary objects of this invention is to provide an improved centrifugal pump system that is of simple design and construction, thoroughly reliable and efficient in operation, and economical to manufacture.

- Another object of this invention is to provide an im proved centrifugal pump system for recirculating a processing solution in a processing machine in which the pump may be rapidly assembled anddisassembled without the aid of special equipment.

Still another object of the invention is to provide an improved centrifugal pump.

A more specific object of the invention is to provide an improved centrifugal pump having a unitary pump assembly of novel design and construction adapted to be readily inserted into and removed from the pump housing.

Objects and advantages other than those set forth above will be apparent from the following description whenread in connection with the accompanying drawings, in which:

FIG. 1 is a side elevation view partially insection, and with portions thereof broken away, of a pump system constructed in accordance with a preferred embodiment of the invention for recirculating a solution within a processing tank; and

FIG. 2. is aperspective view of the pump assembly with a portion thereof broken away.

As shown in the drawings, a centrifugal pump system is disclosed for recirculating a processing solution 2 or the like in a processing tank 3 to assure adequate agitation and mixing of the" processing solution. The pump system essentially comprises a housing assembly 4 having an upper cylindrical housing 5 provided at its lower end with an internal annular, inwardly extending ridge 6.

The ridge 6 has an annular beveled edge 7 at one end merging into the inner surface 8 of upper housing 5, and its other endmerging into an annular seat portion 9. A lower impeller housing v11 is formed integrally with upper housing 5 and is provided with an inlet 12 and an outlet 13. A conduit 14 connects a tap 15 on tank 3 to pump inlet 12. Another conduit 16 connects pump outlet '13 to another tap 17 on tank 3 to provide a closed hydraulic path. The upper housing 5 and tank 3 "ice threaded openings connected by a threaded tube 21 to provide hydraulic communication between upper housing 5 and tank 3 permitting liquid 2 introduced into tank 3 through inlet 22 to enter upper housing 5 and seek a common level in both housing 5 and tank 3.

v The centrifugal pump system further includes a pump assembly 23 as seen in FIG. 2 which is adapted to be received by housing assembly 5 as seen in FIG. 1. The pump assembly 23 comprises an electric motor 24 of any suitable type having a cap 25 secured to the base thereof by screws 26. The cap 25 is substantially circular to conform to the inner surface 8 of upper housing 5 and to be received thereby, and has a positioning lug 27 radially. extending therefrom as best seen in FIG. 2 receivable by a slot 30 in upper housing 5. The lug? and-slot connection 27, 30 cooperates to prevent rotation of pump assembly 23 relative to housing assembly 4. A shaft 28 extends through a central opening formed by cap 25 and has one end drivingly connected to motor 24 and the opposite end secured to an impeller 29- shown as a rectangularly shaped blade. A cover for closing off the open end of impeller housing 11 is shown as a cylindrical disk 31 adapted in an operative position to bear on seat portion 9 as seen in FIG. 1. The disk 31 has a peripheral groove 32 for receiving an O ring 33 of rubber or the like which cooperates with annular ridge 6 in the operative position-to divide housing assembly 4 into upper housing 5 which forms a liquid receiving cavity 34, and impeller housing 11 which forms a cavity 35 for receiving impeller 29. The disk 31 is provided with a central bearing 36 for rotatably supporting shaftZS. The cap 25 and disk 31 are further provided with annular, concentric cups or projections 37, 38,-respectively, for

receiving opposite ends of a cylindrical tube-39. The

tube 39 has an opening 41 near one end to provide hy- '34 so that the liquid entering tube 39' can prevent air from leaking past bearing'36 into cavity 35. The tube 39 also serves as a strengthening member by rigidly connecting disk 31 to cap 35, and further prevents axial displacement of disk 31 on shaft 28.

A fastening device for releasably securing pump assembly 23 to housing assembly 4 after the pump assembly has been disposed therein and moved into the operative position as seen in FIG. 1, comprises a substantially U-shaped spring member 42 constructed of wire and having its ends 43 extending through openings formed in upper housing 5 and bent to prevent withdrawal therefrom. The spring 42 is pivoted upwardly into a substantially vertical position with its cross bar 44 urged into engagement with the top of a projection 45 formed by motor 24. In this position, spring 42 is under tension tending to urge disk 31 of pump assembly 23 downwardly into engagement with seat portion 9 of housing assembly 4.

In the operation of this invention, pump assembly 23, as seen in FIG. 2, is inserted in cavity 34 of housing assembly 4. There is no initial resistance to the doWn ward movement of pump assembly 23 since the inner diameter of upper housing 5 is greater than the outer diameter of O ring 33. Further inward movement of pump assembly 23 into its operative position causes 0 ring 33, which has a greater outer diameter than the inner diameter of annular ridge 6, to strike beveled portion 7 which tends to cam O ring 33 radially inwardly partially flattening it and guiding it into sealing engagement with ridge 6. The downward movement of pump assembly 23 is guided by the operator so that lug 27 is in register with slot 30 in upper housing 5 and is received thereby when pump assembly 23 is in its operative position. The spring 42 is moved upwardly and cross bar 42 thereof urged on top of motor projection 45 for releasably securing pump assembly 23 to housing assembly 4. Energization of motor 24 causes impeller 29 to rotate, drawing liquid or solution 2 out of tank 3 through tap 15, conduit 14 and pump inlet 12 into cavity 35 and expelling it through outlet 13, conduit 16 and tap 17 back into tank 3. This recirculation of the tank liquid assures adequate agitation and mixing of solution 2 contained in tank 3.

The invention has been described in detail with particu- 'lar reference to preferred embodiments thereof, but it will 'be understood that variations and modifications can be effected within the spirit and scope of the invention as described hereinabove and as defined in the appended claims.

I claim:

41. In a centrifugal pump system for use with a tank containing liquid to be circulated, the combination comprising: a housing; a pump assembly for insertion into and removal from said housing and movable into an operative position when inserted therein, said pump assembly including a disk having a peripheral seal member co-operating with the wall of said housing in said operative position to divide said housing into first and second cavities, an impeller disposed in said first cavity, and means for driving said impeller including a shaft extending through said disk, said first cavity having an inlet and an outlet hydraulically connected to said tank; and means for hydraulically connecting said tank to said second cavity for introducing and maintaining a quantity of said liquid in said second cavity to provide a liquid seal for preventing air from said second cavity from passing through said disk and seal member into said first cavity.

2. In a centrifugal pump, the combination comprising: an open-ended cylindrical housing; a pump assembly readily inserted into and removed from said housing and movable into an operative position when inserted therein; said pump assembly including a drive shaft, a cap mounted on one end of said shaft to provide a cover for the open end of said housing in said operative position, said cap having a first axially extending annular projection concentric to said shaft, a seal member mounted on said drive shaft and having a second axially extending annular projection concentric with said shaft, said seal member co-operating with said housing wall in said operative position to divide said housing into first and second cavities, said first cavity having an inlet and outlet to provide for circulation of a liquid therethrough, and said second cavity having an inlet for the introduction of a sealing liquid, a perforated tube encircling said shaft and having one end receivable by one of said first and second projections and the opposite end receivable by the other projection and an impeller mounted on the opposite end of said drive shaft and disposed in said first cavity for driving said shaft when the impeller is disposed in said cavity to draw liquid into said first cavity and to expel it therefrom; and means for releasably securing said pump assembly to said housing in said operative position.

3. The invention according to claim 2 wherein said housing has an annular seat portion, an annular inwardly extending ridge adjacent said seat portion, said ridge having a beveled edge, and said seal member comprises a disk bearing on said seat portion when said pump assembly is in said operative position and having a peripheral groove for receiving an O ring, said beveled edge of said ridge camming said 0 ring, radially inwardly guiding said O ring into sealing engagement with said ridge as said pump assembly is moved downwardly into said operative position.

4. The invention according to claim 2 wherein said means comprises a substantially U-shaped spring having its ends pivotally secured to said housing and a crossbar connecting said ends and bearing upon said pump assembly and holding it in said operative position.

5. In a centrifugal pump 'system for use with a tank containing liquid to be circulated, the combination comprising: an open-ended cylindrical housing; a pump assembly for insertion into and removal from said housing and movable into an operative position when inserted therein, said pump assembly including a drive shaft, a cap mounted on one end of said shaft to provide a cover for the open end of said housing in said operative position, said cap having a first axially extending annular projection concentric with said shaft, 21 seal member mounted on said drive shaft and having a second axially extending annular projection concentric wtih said shaft, said member co-operating with said housing wall in said operative position to divide said housing into first and second cavities, said first cavity having an inlet and an outlet hydraulically connected to said tank, a perforated tube encircling said shaft and having one end receivable by one of said first and second projections and the opposite end receivable by the other projection, and an impeller mounted on the opposite end of said drive shaft and disposed in said first cavity in driven relation with said shaft to draw liquid into said first cavity and to expel it therefrom; and means for hydraulically connecting said tank to said second cavity for introducing and maintaining aquantity of said liquid in said second cavity to provide a liquid seal for preventing air in said second cavity from passing through said seal member into said first cavity.

6. The invention according to claim 5 wherein said housing has an annular seat portion, an annular inwardly extending ridge adjacent said seat portion, said ridge having a beveled edge, and said seal member comprises a disk bearing on said seat portion when said pump assembly is in said operative position and having a peripheral groove for receiving an O ring, said beveled edge of said ridge camming said O ring radially inwardly to guide said O ring into sealing engagement with said ridge as said pump assembly is moved downwardly into said operative position.

7. In a centrifugal pump system for use with a tank containing liquid to be circulated, the combination com o prising:

A--a housing having an annular seat portion and an annular inwardly extending ridge adjacent said seat portion,

(1) said ridge having a beveled edge,

B-a pump assembly for insertion into and removal from said housing and movable into an operative position when inserted therein,

(1) said pump assembly including a seal member comprising a disk bearing on said seat portion when said pump assembly is in said operative position to divide said housing into first and second cavities, said disk having a peripheral groove for receiving an O-ring, said beveled edge of said ridge camming said O-ring into sealing engagement with said ridge as said pump assembly is moved downwardly into said operative position,

Can impeller disposed in said first cavity,

(1) said first cavity having an inlet and an outlet hydraulically connected to said tank,

D--means for driving said impeller including a shaft extending through said seal member, and

Emeans for hydraulically connecting said tank to said second cavity for introducing and maintaining a quantity of said liquid in said second cavity to provide a liquid seal for preventing air from said second cavity from passing through said seal member into said first cavity.

(References on following page) References Cited in the file of this patent 2,875,697 UNITED STATES PATENTS 29151978 2,688,930 De Moss Sept. 14, 1954 2,784,673 Namur Mar. 12, 1957 5 784,682 2,841,087 MacMeekin et a1. July 1, 1958 532,705 2,860,857 Brown Nov. 18, 1958 42,792 2,865,539 Edwards Dec. 23, 1953 311,794

6 Fernstrum Mar. 3, 1959 Schaefer Dec. 8, 1959 FOREIGN PATENTS Great Britain Oct. 16, 1957 Italy Sept. 1, 1955 Sweden July 11, '1917 Switzerland Feb. 15, 1956 

1. IN A CENTRIFUGAL PUMP SYSTEM FOR USE WITH A TANK CONTAINING LIQUID TO BE CIRCULATED, THE COMBINATION COMPRISING: A HOUSING; A PUMP ASSEMBLY FOR INSERTION INTO AND REMOVAL FROM SAID HOUSING AND MOVABLE INTO AN OPERATIVE POSITION WHEN INSERTED THEREIN, SAID PUMP ASSEMBLY INCLUDING A DISK HAVING A PERIPHERAL SEAL MEMBER CO-OPERATING WITH THE WALL OF SAID HOUSING IN SAID OPERATIVE POSITION TO DIVIDE SAID HOUSING INTO FIRST AND SECOND CAVITIES, AN IMPELLER DISPOSED IN SAID FIRST CAVITY, AND MEANS FOR DRIVING SAID IMPELLER INCLUDING A SHAFT EXTENDING THROUGH SAID DISK, SAID FIRST CAVITY HAVING AN INLET AND AN OUTLET HYDRAULICALLY CONNECTED TO SAID TANK; AND MEANS FOR HYDRAULICALLY CONNECTING SAID TANK TO SAID SECOND CAVITY FOR INTRODUCING AND MAINTAINING A QUANTITY OF SAID LIQUID IN SAID SECOND CAVITY TO PROVIDE A LIQUID SEAL FOR PREVENTING AIR FROM SAID SECOND CAVITY FROM PASSING THROUGH SAID DISK AND SEAL MEMBER INTO SAID FIRST CAVITY. 